1-thiocyanomethyl-1h-benzotriazole and 3-thiocyanomethyl-1, 2, 3-benzotriazin-4(3h)-one



2,949,465 Patented. Aug. 16, 1960 '1 -THIOCYANOMETHYL lH-BENZOTRIAZOLE AND '3-THIOCYANOMETHYL-LL3-BENZO- TRIAZlN-4 (3H)-ONE Chien-Pen Lo, Philadelphia, Pa., assignor to Rohm & Haas Company, Philadelphia, Pa., a corporation of Delaware N Drawing. Filed Apr. 15, 1959, Ser. No. 806,432

'3 Claims. (Cl. 260-248) This invention deals with l-thiocyanomethyl-IH- benzotriazole and 3 thiocyanomethyl 1,2,3 benzotriazin-4(3H)-one and with their preparation. These compounds are potent agents for controlling fungi on growing plants.

Some thiocyanates have found use as insecticides and while it has been suggested that thiocyanates may act as fungicides, practical action of this kind is most unusual for members of this class of compounds. It is not possible to predict whether an organic thiocyanate will have fungicidal action.

These compounds are prepared by reacting the corresponding halomethyl compound with a salt of thiocyanic acid. As most suitable starting materials, there is used 1 chloromethyl 1H benzotriazole, 1 bromomethyl- 1H benzotriazole, 3 chloromethyl 1,2,3 benzotriazin 4(3H) one, or 3 bromomethyl 1,2,3 benzotriazin-4(3H)-one, the halogen of the halomethyl groups having an atomic weight of at least 35. The salt of thiocyanic acid may be ammonium, sodium, potassium, calcium, or the like thiocyanate.

The reaction of these materials is carried out preferably in an inert, volatile organic solvent, such as acetone, ethylene dichloride, benzene, or lower alkanol. A water-miscible solvent is preferred.

Reaction mixture is heated between 50 C. and 125 C. The desired product is isolated by removing solvent or precipitating the thiocyano compound by dilution of reaction mixture with water. If desired, the product may be purified as by crystallization.

Additional details of preparation are given in the following illustrative examples, wherein parts are by weight unless otherwise specified.

Example 1 that of the designated structure, there being 29.5% of nitrogen and 16.8% of sulfur (theory 29.2% and 16.6% respectively) It has the structure When the corresponding bromomethyl compound is used, the same end product is obtained. Instead of the 1- chloromethylor l-bromomethyl-lH-benzotriazole, there may be used corresponding starting materials having one or more unreactive substituents in the phenyl ring thereof, such as chlorine, nitro, or alkyl.

Example 2 There are mixed 20 parts of 3-chloromethy1-1,2,3- benzotriazin-4(3H)-one, 10 parts of potassium thiocyanate, and parts of acetone. The mixture is heated under reflux with stirring for two hours. It is then poured into cold water. A solid separates, is filtered off, washed, and dried. This product, amounting to 21 parts, contains by analysis, 24.9% of nitrogen and 13.3% of sulfur and corresponds by composition to 3-thiocyanomethyl 1,2,3 benzotriazin 4(3H) one, for which the theoretical values are 25.7% of nitrogen and 14.7% of sulfur. The compound melts at ll8120 C. It has the structure ITICHzSCN In the standard fungitoxicity test performed with spores of test organisms on slides l-thiocyanomethyl-1H-benzotrazole gave an ED value of less than 5 p.p.m. against Alternaris solani and against Monalim'a fructicola, and of 5-10 p.p.m. against Stemphylium sarcinaeforme.

It was not phytotoxic to young tomato plants when applied in a 1% spray.

In the standard fungitcxicity test on slides 2-thio cyanomethyl 1,2,3 benzotriazin 4(3H) one gave ED values of less than 5 p.p.m. against Alternaris solani, of 5-10 p.p.m. against Monoliniw fructicola, and of 10-50 p.p.m. against Stemphylium swrcin'aeforme.

This compound was non-phytotoxic to young tomato plants which were treated with a spray containing 1% thereof.

These compounds were also evaluated for their activity against late blight on tomato plants. In this evaluation test young plants are sprayed with a suspension of the compound under test at several concentrations, dried and sprayed with a suspension of spores of Phytophthora infestans. Some plants are sprayed only with a suspension of spores as controls. All plants are held under carefullycontrolled conditions of temperature and moisture. Counts are made of lesions which result and the ED value determined.

ED values of were found for both of the compounds prepared in Examples 1 and 2. At the same time a standard zineb was applied. It gave an ED value of 360.

The compounds of this invention are generally used in compositions in which the active agent is mixed with an inert carrier. Dusts may be prepared by mixing a compound with a finely divided solid, such as talc, clay, pyrophyllite, diatomaceous earth, hydrated silica, or magnesium carbonate. If desired, wetting and/or dispersing agents may be admixed. When the proportion of these is increased, there results a wettable powder, which may be taken up in water and applied from a spray.

The dusts may contain 1% to 15% of the thiocyanomethyl compound, While the wettable powders may contain up to 50% or even more of one or both of these compounds.

A typical formulation of a wettable powder comprises 20% to 50% of active agent, 45% to 75% of one or more finely divided solids, 1% to 5% of a wetting agent, and 1% to 5% of a dispersing agent. Typical wetting agents include sodium dodecyl sulfate, sodium sulabove thiocyanomethyl compounds, including insectifosuccinate, sodium alkylbenzenesulfonates, alkylphencides, miticides, and other fungicides.

oxypolyethoxyethanol, or other non-ionic, such as the I claim:

ethylene and/or propylene oxidetcondensates with long 1. A compound selected from the class consisting of Chained y1 acids, 316011018, l V 5 l-thiocyanomethyl-IH-benzothiazole and 3-thiocyano- Emulsifiable liquid concentrates may also be prepared methyl-1,2,3-benzotriazin-4'(3H)-one.

with an organic solvent and a; solvent-soluble emulsifier, 2. p hi h l-1H b i 1 such as one or more non-ionicrsurface active agents, or other solvent-soluble wetting agent.

Other pesticidal. agents may be used along. with the 10 N0 e erences clted.

3. 3-thiocyanomethyl-1,2,3-bei1zotriazin-4 3H) -one.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,949,465 August 1960 Chien-Pen Lo It is hereby certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 5, for "-lI-I-benzothiazole" read 1Hbenzotriazo1e Signed and sealed this 4th day of April 1961 (SEAL) Att t; W. Jami A ARTHUR w. CROCKER Attesting Oflicer Acting Commissioner of Patents 

1. A COMPOUND SELECTED FROM THE CLASS CONSISTING OF 1-THIOCYANOMETHYL-1H-BENZOTHIAZOLE AND 3-THIOCYANOMETHYL-1,2,3-BENZOTRIAZIN-4(3H)-ONE.
 3. 3-THIOCYANOMENTHYL-1,2,3-BENZOTRIAZIN-4(3H)-ONE. 